Green cities provide a mental health boost that lasts

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Ian Alcock receives funding from the Economic and Social Research Council. The European Centre for Environment and Human Health is funded by the European Regional Development Fund and the European Social Fund Convergence Programme for Cornwall and the Isles of Scilly.

It’s been established that enjoying green spaces in otherwise grey urban areas can lead to improved mental health for city-dwellers. But new research has revealed how surprisingly quickly those benefits appear, and how long they last.

Research from the University of Exeter’s European Centre for Environment and Human Health found that people living in towns and cities with more parks and gardens tend to report greater well-being than those without. But it also revealed that relocating to a greener part of town led to improvements in their mental health that lasted for at least three years.

There are other life changes that influence mental health, and many of those do so gradually, or else seem to be only short-lived. Job promotion and marriage boost well-being in the short term, for example, and financial windfalls can lead to gradual improvements. But these new findings indicate that simply increasing the ratio of green to grey in urban neighbourhoods is likely to provide benefits that are not only immediate, but which continue to deliver benefits long afterwards.

The research, just published in the journal Environmental Science and Technology, used data from the British Household Panel Survey, a long-running household survey project, based in Essex. We analysed five consecutive years of mental health questionnaires, answered by people who had relocated to a different residential area between the second and third years.

Two groups of people were tracked: 600 who moved to greener urban areas, and 470 who moved to areas that were less green. While the group who moved to greener suburbs showed significant improvements for all three years after their relocation, there was not a corresponding decline in mental health for those who moved to less green areas. There was, however, a decline in the mental health of these people in the year before they moved. It’s not clear whether this was some degree of dread at the anticipated relocation, or whether it was declining well-being that lay behind the decision to relocate.

Studying people who relocate from one area to another can offer insights into the effects of town planning decisions that alter the make-up of city neighbourhoods. It’s hard to design and carry out experiments that involve the radical “re-greening” and “de-greening” of our cities to see what effects these processes have. But we can get important clues by looking at the average effects that result from the loss or gain of green space after someone has moved home.

Endless cities risk much grey, not enough green.wilhelmja

The benefits we’ve observed have implications for planning policy, which aims to improve public health through urban design. Our findings suggest that improved mental health is not the result simply of the novelty of living in a greener area, which might wear off quickly. Creating parks and green corridors in our increasingly urban landscapes could represent good value-for-money public health services, delivering long term benefits to community health.

How good is green space for urban residents? An earlier study published in Psychological Science estimated the effects on mental health delivered by a 1% difference in urban green space, also working with Household Panel Survey data from England and controlling for the effects of personality. The study found that living in an area with high rather than low green space was equal to roughly a third of the benefit of being married, and a tenth of the benefit of having a job.

Importantly, in estimating the effects of green space, the team accounted for other factors which can influence mental health, such as the individuals’ income, family and employment circumstances. They also accounted for area factors which may overlap with urban greenness, such as the socio-economic profile of the neighbourhood.

Depression and depressive disorders are now the leading cause of disability in middle to high income countries – mental health is a critical public health issue of modern times. And it’s quite possible this trend is related to how quickly the world’s population is moving to the city: in the world’s more developed regions, more than three-quarters of the population live in urban environments, with the reduced access to the natural world that brings.

So while these studies don’t show that relocating to a greener area will definitely increase happiness, the findings fit with other experimental work that shows how short spells in a green space does improve people’s mood, and cognitive functioning. Our findings join those from earlier epidemiological studies that clearly demonstrate the link between health benefits and green space.